Sally Furniss
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CK2beta gene silencing increases cell susceptibility to influenza A virus infection resulting in accelerated virus entry and higher viral protein content
Henju Marjuki
, Christoph Scholtissek , Hui-Ling Yen and Robert G Webster
Journal of Molecular Signaling 2008, 3:13doi:10.1186/1750-2187-3-13
<table cellpadding="0" cellspacing="0"> <tbody> <tr> <td>
</td></tr><tr> <td>Published:</td> <td>23 July 2008</td> </tr> </tbody> </table>Abstract (provisional)
Background
Influenza A virus (IVA) exploits diverse cellular gene products to support its replication in the host. The significance of the regulatory (beta) subunit of casein kinase 2 (CK2beta) in various cellular mechanisms is well established, but less is known about its potential role in IVA replication. We studied the role of CK2beta in IVA-infected A549 human epithelial lung cells.
Results
Activation of CK2beta was observed in A549 cells during virus binding and internalization but appeared to be constrained as replication began. We used small interfering RNAs (siRNAs) targeting CK2beta mRNA to silence CK2beta protein expression in A549 cells without affecting expression of the CK2alpha subunit. CK2beta gene silencing led to increased virus titers, consistent with the inhibition of CK2beta during IVA replication. Notably, virus titers increased significantly when CK2beta siRNA-transfected cells were inoculated at a lower multiplicity of infection. Virus titers also increased in cells treated with a specific CK2 inhibitor but decreased in cells treated with a CK2beta stimulator. CK2beta absence did not impair nuclear export of viral ribonucleoprotein complexes (6 h and 8 h after inoculation) or viral polymerase activity (analyzed in a minigenome system). The enhancement of virus titers by CK2beta siRNA reflects increased cell susceptibility to influenza virus infection resulting in accelerated virus entry and higher viral protein content.
Conclusions
This study demonstrates the role of cellular CK2beta protein in the viral biology. Our results are the first to demonstrate a functional link between siRNA-mediated inhibition of the CK2beta protein and regulation of IVA replication in infected cells. Overall, the data suggest that expression and activation of CK2beta inhibits IVA replication by regulating the virus entry process and viral protein synthesis.
The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.
http://www.jmolecularsignaling.com/content/3/1/13
Henju Marjuki
, Christoph Scholtissek , Hui-Ling Yen and Robert G Webster Journal of Molecular Signaling 2008, 3:13doi:10.1186/1750-2187-3-13
<table cellpadding="0" cellspacing="0"> <tbody> <tr> <td>
</td></tr><tr> <td>Published:</td> <td>23 July 2008</td> </tr> </tbody> </table>Abstract (provisional)
Background
Influenza A virus (IVA) exploits diverse cellular gene products to support its replication in the host. The significance of the regulatory (beta) subunit of casein kinase 2 (CK2beta) in various cellular mechanisms is well established, but less is known about its potential role in IVA replication. We studied the role of CK2beta in IVA-infected A549 human epithelial lung cells.
Results
Activation of CK2beta was observed in A549 cells during virus binding and internalization but appeared to be constrained as replication began. We used small interfering RNAs (siRNAs) targeting CK2beta mRNA to silence CK2beta protein expression in A549 cells without affecting expression of the CK2alpha subunit. CK2beta gene silencing led to increased virus titers, consistent with the inhibition of CK2beta during IVA replication. Notably, virus titers increased significantly when CK2beta siRNA-transfected cells were inoculated at a lower multiplicity of infection. Virus titers also increased in cells treated with a specific CK2 inhibitor but decreased in cells treated with a CK2beta stimulator. CK2beta absence did not impair nuclear export of viral ribonucleoprotein complexes (6 h and 8 h after inoculation) or viral polymerase activity (analyzed in a minigenome system). The enhancement of virus titers by CK2beta siRNA reflects increased cell susceptibility to influenza virus infection resulting in accelerated virus entry and higher viral protein content.
Conclusions
This study demonstrates the role of cellular CK2beta protein in the viral biology. Our results are the first to demonstrate a functional link between siRNA-mediated inhibition of the CK2beta protein and regulation of IVA replication in infected cells. Overall, the data suggest that expression and activation of CK2beta inhibits IVA replication by regulating the virus entry process and viral protein synthesis.
The complete article is available as a provisional PDF. The fully formatted PDF and HTML versions are in production.
http://www.jmolecularsignaling.com/content/3/1/13